FRIDAY, June 16, 2017 (HealthDay News) -- Many indoor tanning salons in the United States would let underage customers tan despite government bans, a new study finds.

"Enacting well-crafted age restriction laws to maximize compliance through enforcement of penalties on the state level and moving towards a national ban with similar accompanying strong enforcement . . . [is] essential to reduce skin cancer risk in the vulnerable youth population," said study leader Leah Ferrucci.

She is an associate research scientist in epidemiology and a lecturer at the Yale School of Public Health.

For the study, researchers posing as underage consumers phoned tanning salons in California, Connecticut, Delaware, Hawaii, Illinois, Louisiana, Minnesota, Nevada, New York, Oregon, Texas, Vermont, Washington and the District of Columbia. All had banned indoor tanning by anyone under age 17 or 18 at the time of the study.

About one-fifth of the salons said they would let underage customers use their tanning facilities, according to the report, which was published online recently in the journal Translational Behavioral Medicine.

Compliance was lowest in the South (about 71 percent) and highest (nearly 88 percent) in states where bans had been in place for at least two years, the findings showed.

The investigators also found that some salons gave customers false or misleading health information. Vitamin D production, cosmetic reasons and treatment of skin diseases were often claimed as benefits of indoor tanning, and 10 percent of salons said it posed no risks.

Only 20 percent told customers it could cause skin cancer, the researchers said in a journal news release.